The use of saline and the bulb syringe
technique can significantly help clear the
nasal passage of a baby and facilitate him / her in
breathing properly.
As I mentioned earlier, if you want to learn more about deep
nasal breathing, I'd recommend you read «Body, Mind, and Sport» by John Doullard, and to learn more about rhythmic
breathing techniques, check out «Running on Air» by Budd Coates.